A hydrocarbon recovery operation involving drilling a wellbore into a subterranean formation would traditionally isolate the zones of a wellbore annulus, for multi-pay-zone gravel packing, with packers. This type of procedure required many trips in and out of the wellbore and translated into very high expenses for rig time.
In the past, the fracturing and gravel packing equipment was run into cased and perforated holes, along with an isolation packer. The packer was set to isolate the lowermost zone, and the isolated zone was then fractured below that packer. Thereafter, gravel would be delivered outside a screen through a crossover to fill the annular space around the screen with gravel. The packer would then remain in the zone to be gravel packed along with the screens. The crossover, and a wash pipe associated with the screens, were subsequently pulled out of the annulus through the already set packer. After isolating, fracturing, and gravel packing that zone, another trip into the wellbore would occur to gravel pack the zone adjacent to the most recent gravel packed zone. This process continued until all zones or sections of a continuous zone were isolated, fractured, and gravel packed.
It would be desirable if a method and apparatus were devised for isolating and completing multi-zone gravel packs at a reduced cost, as well as a reduced number of trips into and out of the wellbore.